diff --git a/lib/layouts/theorems-ams-bytype.inc b/lib/layouts/theorems-ams-bytype.inc
index f784c3882e..25a034421e 100644
--- a/lib/layouts/theorems-ams-bytype.inc
+++ b/lib/layouts/theorems-ams-bytype.inc
@@ -23,7 +23,7 @@
 
 Format 89
 
-Input theorem-counters-bytype.inc
+Input theorems-counters-bytype.inc
 
 OutlinerName thm "Definitions & Theorems"